Dual reamer driver

ABSTRACT

The disclosure illustrates a dual driver for surgical reamers in which either of a crossbridge and crossbar style reamers are axially inserted in the distal end of a central shaft for the reamer driver. A pair of L shaped grips are adapted to connect and disconnect the different style of reamers by the movement of an external sleeve biased towards the connection position. Movement of the sleeve away from the distal end allows an internal plunger to cam the grips to an open position and urge the appropriate reamer from the tool driver directly in an axial direction.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 12/233,149,entitled “DUAL REAMER DRIVER”, filed Sep. 18, 2008, which isincorporated herein by reference. U.S. patent application Ser. No.12/233,149 is a non-provisional application based upon U.S. provisionalpatent application Ser. No. 60/973,919, entitled “AUTOMATIC DUALCONNECTION REAMER DRIVE”, filed Sep. 20, 2007, which is incorporatedherein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to orthopedic surgical reamers and morespecifically to drivers for such tools.

In the field of orthopaedic surgery, it is often necessary to removebone material to enable implantation of prosthesis to repair joints inthe human body. Patella cutters and acetabular reamer cups and glenoidreamers are surgical tools which are used in surgery for the insertionof artificial joints. Acetabular reamer cups are used to cuthemispherical cavities in pelvis bones for the insertion of artificialhip joints. Patella cutters are used to shape the underside of thepatella or knee cap during knee replacement surgery. Glenoid reamers areused to cut hemispherical cavities in shoulder bones for the insertionof artificial shoulder joints. Patella cutters have a complexarrangement of precisely shaped cutting edges arranged around an axis ofrotation for cutting the patella. Acetabular reamer cups and glenoidreamers have a complex arrangement of cutting edges arranged on aspherical surface around the axis of rotation of the cup.

A number of tools have been developed for this purpose and includereamers having generally semi-hemispherical configuration with cuttingelements on them so that a corresponding semi-hemispherical hollow canbe formed in the bone material for providing a foundation for the repairof the joint.

There are two major driver styles in the field, one of which is for theOthy style manufactured by Symmetry Medical, Inc. and the other stylemanufactured by Precimed SA of L'Echelette, Switzerland. Although theseboth have semi-hemispherical cutting heads, they have differentinterfaces between driving tools with which they are associated. TheOthy style has a crossbridge element. This element is a bar extendingbetween the circumference of the hemisphere and having a circularexpanded section in the middle. Numerous arrangements are available forsecuring this device as exemplified by U.S. Pat. No. 6,854,742.Alternatively, the Precimed reamer has a crossbar shape in which twocircular cross section bars intersect at the center and extend to thewalls of the hemisphere. An example of a driver for this type is foundin U.S. Pat. No. 5,658,290 in which a bayonet interconnection isprovided between the reamer and the driver.

Typically, surgeons use specialized drivers for each of the reamers. Thedrivers connect to a source of power and have appropriate handles forguiding the operation of the reamer by a surgeon. If a surgeon has oneof the adaptors, it is difficult to utilize the other type of reamersince it requires a specialized driver for that reamer. It has beenproposed in U.S. Pat. No. 7,115,119 to provide a dual adapter thataccommodates both the Othy and the Precimed reamers. However, this styleof dual reamer requires a bayonet interconnection in which theassemblies are inserted axially and then a rotational movement, inaccordance with a bayonet connection, is provided to lock the elementsin place. This type of action slows the process of utilizing a newreamer because of the additional movement, But, more than that, therelease of the device, after it has been in the surgical environment, ismore difficult because it requires holding the reamer to reverse therotational movement and then axial movement to finally free the reamer.

What is needed in the art, therefore, is a tool driver for surgicalreamers that enables rapid and immediate connection and disconnection ofthe reamers.

SUMMARY OF THE INVENTION

In one form, the invention is a tool driver for multiple styles ofsurgical reamers. The driver includes a central shaft rotatable about alongitudinal axis and having a proximal driven end and a distal end. Areamer receiver is carried by the distal end of the shaft and thereceiver has axially facing sets of recesses for receiving at least twodifferent styles of surgical reamers. A gripping device is provided forreleasably holding the surgical reamer assemblies in place, thereleasable holding device permitting axial removal of the differentstyles of surgical reamers.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of an embodiment of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is an exploded perspective view of a tool driver in accordancewith the present invention;

FIG. 2 is a longitudinal section view of the tool driver shown in FIG.1;

FIG. 3 is an expanded detailed view of a portion of the tool driver inFIGS. 1 and 2 taken in the same plane as FIG. 2;

FIG. 4 is an enlarged detailed view of a portion of the tool drivershown in FIG. 2 taken on a plane at 90 degrees to the plane of FIG. 2;

FIG. 5 is a side view of an element of the tool driver shown in FIGS.1-4; and

FIG. 6 is a top view of the element shown in FIG. 5.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplification set out hereinillustrates one embodiment of the invention and such exemplificationsare not to be construed as limiting the scope of the invention in anymanner.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows an exploded view of a reamer driver 10 in accordance withthe present invention. Reamer driver 10 has a central shaft 12 rotatableabout a longitudinal axis A at an RPM that is appropriate for removal ofmaterial during a surgical procedure. Shaft 12 has a proximal end 14with an interface having an appropriate to receive a power element toproduce the correct torque and RPM to perform the surgical removal ofmaterial.

Central shaft 12 has a distal end 16 for receiving one of a plurality ofdifferent styles of surgical reamers. As shown particularly in FIGS. 3and 4, distal end 16 has a plurality of recesses integrally formed withthe end of shaft 12. It should be apparent, however, to those skilled inthe art that the recesses may be formed in a separate element that isaffixed to the end of shaft 12. A pair of recesses 18 are semicircularin cross section as shown in FIG. 3. Recesses 18 are formed in portionsof the distal end 16 offset from the central axis A and permit movementdirectly in an axial direction as shown in FIG. 3. FIG. 4 shows a pairof recesses 20 including a base 22 and a shoulder 24 connecting tosidewalls 26. Recesses 20 are positioned at 90 degrees relative torecesses 18.

As stated previously there are two major styles of reamers in thesurgical field, one of which is a crossbar and the other of which is acrossbridge. The crossbar interface is illustrated by dashed lines 28,shown in FIG. 3 and FIG. 4. It is to be noted that the base ofsemicircular recess 18 and recess base 22 are in the same plane so thatthe interface for the crossbar reamer 28 is positioned in a common planeto stabilize it. The other surgical reamer is an Othy crossbridge reamerhaving a circular center and two radially extending bars illustrated bydashed line 30. The crossbridge reamer 30 rests on the shoulder 24. Thecrossbridge reamer is also moveable into and out of the recesses 20 inan axial direction as illustrated in FIG. 4.

The different styles of reamers 28 and 30 are retained within therecesses 18 and 24 by grips 32 and 34 shown in FIGS. 2 and 3 and indetail in FIGS. 5 and 6. The grips 32 and 34 are identical so thatreference characters used in FIGS. 5 and 6 are applicable for bothgrips. Grips 32-34 comprise base elements 36 and 37 having centralaligned bores 40 to provide a pivotal mounting on central shaft 12.Bases 36 extend to integral gripping elements 38 having an L-shapedextension 41 so that the grips 32-34 form an L-shape with a pivotalmounting at one end of the L. The extension 41 has a gripping surface 42with a contour that provides a negative angle with respect to the centerof bore 40 so as to accommodate varying thicknesses of reamers.Generally speaking the surface 44 has approximately a 4 degree anglewith respect to a plane at right angles to a line extending through bore40. An intermediate section 46 has a camming surface 48 projectingdownward as shown in FIGS. 5 and 6 to interact with elements of thereamer driver 10 disclosed below.

The grips 32 and 34 are pivotally connected to shaft 12 at surfaces 50with a through hole 52 by a pin 54 extending through bore 40 and throughhole 52. Thus, the grips 32 and 34 are mounted so as to grip or releasethe respective reamers 28 and 30 in an axial direction. FIG. 2 shows thegrips 32 and 34 in the retention position.

Grips 32 and 34 are biased to the open position permitting removal ofthe reamers 28 or 30. As shown in FIGS. 1 and 2, this is done by acentral plunger 56 received in an axial bore 58 of central shaft 12.Plunger 56 is retained within the bore 58 by a removable ring 60 and isbiases towards the left by a spring 62 retained within bore 58. Plunger56 has a shoulder 64 that acts as a camming surface for thecorresponding camming surface 48 on grips 32-34 so as to displace themin a radially outward direction upon axial movement of plunger 56towards the distal end of shaft 12. Thus, in the absence of anyrestraining element, the grips 32 and 34 are urged to their openposition.

The grips 32-34 are urged to the closed position illustrated in FIG. 2by a sleeve 66 telescoped over shaft 12. Sleeve 66 has an inwardlyfacing shoulder 68 which abuts a corresponding outwardly facing shoulder70 on shaft 12 to limit the left most position of sleeve 66. Sleeve 66has a suitable serrated gripping surface 67 to enable manualmanipulation. Sleeve 66 is urged to the leftmost position by a spring 74retained over shaft 12 and abutting a protective sleeve 76, alsotelescoped over shaft 12.

Protective sleeve 76 is retained on shaft 12 by a pin 78 received in across bore 80 of shaft 12 and yieldably urged to the position shown inFIG. 2 by a spring 82. An appropriate cap 84 retains spring 82 withinthe bore 80. A retention sleeve 86 is appropriately affixed to theproximal end 14 of shaft 12 so as to limit the rightmost movement ofprotective sleeve 76.

In order to facilitate cleaning of the reamer driver, radial passages 88are provided from recess 58 to the exterior and a central passage 90 isprovided in plunger 56. In addition, plunger 56 has cross semicircularrecesses 92 at 90 degrees to one another to abut the crossbars of reamerstyle 28 so as to further stabilize it.

The reamer driver 10 is operated by pulling sleeve 66 to the right asviewed in FIG. 2 so as to free the grips 32 and 34 and permit the spring62 to displace the plunger 56 axially so that shoulder 64 urges thecamming surface 48 radially outward. The arc of movement is sufficientto permit the surfaces 42 of grips 32-34 to provide axial clearancepermitting removal or installation of the reamer driver styles 28 and 30in an axial direction only. While the sleeve 66 is retracted, eitherreamer driver style 28 or 30 is axially inserted into the appropriaterecesses and the plunger 56 is displaced to the right as shown in FIG.2. In the case of reamer style 28, the semicircular recesses 92 embracethe crossbars so as to stabilize the reamer. In the case of reamer style30, the end of plunger 56 abuts the undersurface of the crossbridgereamer 30. The displacement of the plunger 56 to the right permits thegrips 32 and 34 to be acted on by sleeve 66 as urged by spring 74. Thisaction holds the drivers in place for a surgical procedure. When thesurgical procedure is completed, the sleeve 66 is simply displacedaxially to the right as shown in FIG. 2 and the plunger 56 automaticallyurges either driver style from the driver assembly, thus eliminatingmultiple movements during a surgical procedure.

In addition to providing a simplified axial movement for connection andremoval, the displacement of pin 78 permits the protective sleeve 76 tobe moved to the right against retention sleeve 86, thus allowing totalexpansion of the grips 32 and 34 for cleaning. The radial passagesprovided in plunger 66 and in the sidewall of recess 58 also facilitatethe cleaning of the assembly.

The angle provided on surface 44 of grip 32-34 enables the retention ofa range of thicknesses for the reamers 28 and 30.

While this invention has been described with respect to at least oneembodiment, the present invention can be further modified within thespirit and scope of this disclosure. This application is thereforeintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

What is claimed is:
 1. A tool driver for a style of surgical reamer,said driver comprising; a central shaft rotatable about a longitudinalaxis and having a proximal driver end and a distal end; a reamerreceiver carried by the distal end of the said shaft, said reamerreceiver having an axially facing recess for receiving a style ofsurgical reamer; a gripping device in said recess for releasably holdingsaid surgical reamer assemblies in place in said recess, said grippingdevice comprising at least one pair of L-shape elements and a sleeve;said at least one pair of L-shape elements are pivotally mounted toadjacent opposite sides of said central shaft at said distal end andbeing pivotal between a retention position and an open positionpermitting direct axial removal and installation of the style ofsurgical reamer, each of said L-shaped gripping elements comprising afirst section at a first end for pivotal mounting to said central shaft,a second opposing free end having an extension extending radially inwardfor capturing and holding different style reamers in said recesses, andan intermediate camming surface facing said longitudinal axis of saidcentral shaft; and said sleeve is telescoped over said central shaft,wherein said sleeve being yieldably urged to hold said L-shape grippingelements in place; said central shaft further comprising an axial boreat said distal end and a plunger being axially received in said axialbore; said plunger interacting with said gripping device to urge said atleast one pair of opposing L-shaped gripping elements from saidretention position to said open position upon axial movement of saidplunger in said bore, said plunger having a surface at a distal end ofsaid plunger for abutting and stabilizing said style of reamer therein;wherein said plunger further comprises a shoulder that acts as a cammingsurface for interacting with said camming surface of said L-shapegripping elements and urges said at least one pair of L-shaped grippingelements from said retention position to said open position upon axialmovement of said plunger in said bore; a spring being retained withinsaid axial bore for yieldably urging said plunger in an axial directionrelative to said central shaft and urging said L-shape gripping elementsto said open position thereby releasing said style of reamer, such thatin said open position said style of reamer is automatically released andejected from said central shaft in an axial direction.
 2. The tooldriver as claimed in claim 1, wherein said style of surgical reamer is acrossbridge style reamer having an interface including a centralcircular disk and opposed tabs extending radially outward from saidcentral disk and wherein said reamer receiver is configured to receivesaid crossbridge style reamer.
 3. The tool driver as claimed in claim 2,wherein said reamer receiver has a central circular recess oriented tobe at right angles to the longitudinal axis of said central shaft and apair of opposed rectangular recesses extending radially outward fromsaid central circular recess for receiving said crossbridge stylereamer.
 4. The tool driver as claimed in claim 3, wherein said L-shapedelements are positioned to grip the radially extending tabs of saidcrossbridge reamer.
 5. The tool driver as claimed in claim 1, whereinsaid style of reamer is a crossbar style reamer having an interfaceincluding a pair of circular cross section bars intersecting at rightangles and wherein said receiver is configured to receive said crossbarstyle reamer.
 6. The tool driver as claimed in claim 5, wherein saidreamer receiver includes a pair of semi-circular cross section recessesextending at right angles relative to one another and intersecting atthe longitudinal axis of said central shaft for receiving said crossbarinterface.
 7. The tool driver as claimed in claim 6, wherein saidL-shaped elements are positioned to grip one of said intersecting bars.